(a) Field of the Invention
This invention relates to detecting devices and more particularly to a device for detecting variations of the shape and kind of an object to be examined wherein the light amounts of the respective portions of the image of the object as projected on a focusing glass by an objective are converted to electric signals by photoelectric converting elements and the signals are treated.
(b) Description of the Prior Art
For example, on an automatic assembling line, as the uniformity of component parts to be assembled is required, the component parts fed on the assembling line must be always examined and those out of the standards in respect of the shape and material must be removed out of the line. Also, in an automatic charging system for charging a container with a fixed amount of such liquid as a drink or chemical solution, it is necessary to examine whether the container is charged with a predetermined amount of the liquid when or after the charging is completed.
The detecting device of this kind can be conveniently used in such automatic assembling line and automatic charging system as are described above. Various types of the detecting device of this kind have been already suggested and can be largely classified into two kinds. That is to say, one of them is a system wherein many photoelectric converting elements are arranged on the entire focusing plane of an object to be examined and electric signals from the respective elements are taken out in turn and are treated through electronic circuits. The other is a system wherein an image is scanned with one or a comparatively few photoelectric converting elements and electric signals coming out of them are treated through electronic circuits.
In the former type, in order that the slightest variation of the object or image may be positively detected, many elements must be densely arranged. In the latter type, as it takes some time to scan the entire focusing plane and the electric signals continuously taken out of the elements must be treated in turn, in order to detect the variation of the image, there is required a device for memorizing the electric signals taken out of the respective portions of the entire image plane. For such reasons, both of the conventional detecting devices have defects that the formation is complicated and the price is high.